This invention relates to a fluid line swivel joint connector, and more particularly to a swivel joint connector having fluid input and output ends for communicating a first fluid conduit rotatably about a first axis at one end to a second fluid conduit rotatable about a second axis at the other end, one of the conduits being flexible and the other being rigid, the connector behind adapted to align the longitudinal axis of the end attached to the flexible conduit with the direction of any tensile force applied through the flexible conduit. The swivel joint may be mounted in a fuel line of a fuel dispensing station so that the swivel joint may permit a dispensing nozzle to pivot relatively to the fuel line, or it may permit a first section of the line to pivot relatively to another section, and the pivot joint may have detachable means which uncouples to shut flow communication at the joint when the tensile load at the joint is above a predetermined level.
It is known in the fuel dispensing art to include a swivel connector at the dispenser/hose interface so that twisting loads applied to the dispenser are not transmitted to the hose resulting in twisting thereof. Such swivels merely permit the dispenser, such as a fuel dispensing nozzle, to be pivoted about one or more axes relative to the axis of the hose, the swivel permitting flow communication means between the hose and the dispensing device.
Additionally, it is known to utilize quick disconnect or breakaway couplings in the fuel line spaced from the dispenser so that if a vehicle is driven away from the fuel dispensing station before the dispensing nozzle is removed from the filler neck of the vehicle, an uncoupling will result, shutting the flow of fuel and preventing the volatile fuel to be spilled due to either a dislodging of the moorings of the fuel dispensing station, breakage of the hose, or other failure of the fuel dispensing system. The prior art has proposed a number of decouplers which are acuated by a tensile force in the line. In our aforesaid copending application Ser. No. 07/107,947, the problems and deficiencies of the prior art decoupler units was described and combination swivel joint and quick disconnect coupling devices are disclosed and claimed, the devices having coupling means between first and second body members which swivel relatively to one another and the coupling means acting normally to connect the body members in flow communication and for decoupling when an external tensile force above a predetermined level is applied to the fuel line, and valving acting for shutting flow communication when the body members are decoupled.
There are, however, certain occasions wherein the direction of the external tensile force applied to the fuel line is such that both in conventional swivel connectors and in the combination swivel joint quick disconnect couplings or connectors disclosed in the aforesaid patent application where the tensile force will not permit the swivel joint to pivot, i.e., the reaction force to the external tensile force does not act in a direction which effects rotation about the pivot axis. Such conditions may occur when a swivel joint having one end connected to a flexible fluid conduit, such as a hose, and another end connected to a rigid fluid conduit, such as a nozzle, does not permit the end connected to the flexible conduit to align itself with the direction in which the tensile force is applied. When this occurs a bending moment results which may act to shear the interconnecting members of the joint. For example, if the external tensile force is applied in the same plane as that of the pivot axis of the swivel joint and of the axes of the inlet and outlet to the swivel joint, the reaction to that force can only be resisted by the interconnecting members of the joint, and if the force is substantial a shearing of the elements may occur.